Inductive energy transfer in a contactless connector is known in which an inductor or a magnetic winding in a primary side power transmission device is magnetically coupled with an inductor or a magnetic winding in a secondary target device. Energy is inductively transferred between the primary side and the secondary side of the contactless connector; if the secondary side is removed from the primary side, the energy transfer is interrupted. In this context, the term “contactless” is used to indicate that energy transfer can be realized without any ohmic connection between corresponding electrical contacts on the primary side and secondary side, respectively.
Omission of electrical contacts is of great importance for many applications, such as in applications involving electric connections between a power source and sink in which technically complex plugs and cables can be avoided by application of inductive energy transfer (“IE”). Further, technical energy supply system components based on IE can be protected from environmental impacts without using mechanically complex connectors. Moreover, in some application areas for IE, the use of electrical connections has to be avoided in light of technical feasibility. Furthermore, the use of IE can improve the reliability of systems in which the devices and contacts are exposed to high stress, such as systems with rotating or moveable parts prone to wear due to friction.
A contactless connector system is disclosed in European patent specification EP 2581994 B1. The contactless connector system has primary side and secondary side inductive couplers that can be mated for wirelessly transmitting electric power from the primary to the secondary. A bi-directional data transmission is also established between two antennas, thereby establishing a radio frequency data link between the two parts of the connector system.
Another known contactless connector system is shown in FIG. 1. This contactless connector system 200 comprises a power transmitting connector 202 and a power receiving connector 204. The power transmitting connector 202 has a primary inductive coupler Lp which is powered from an input power source. The input power may for instance be a DC power which is transformed into an alternating voltage by means of a DC/DC converter 206 and a subsequent DC/AC converter 208. As this is schematically shown in FIG. 1, the inductive coupler Lp is part of a resonant circuit 210 which comprises a capacitor Cp in parallel to the inductive coupler Lp.
When the two mating surfaces 212, 214 of the power transmitting connector 202 and the power receiving connector 204 are sufficiently close, the secondary inductive coupler Ls is magnetically coupled to the primary inductive coupler Lp. The secondary inductive coupler Ls is part of a secondary resonant circuit 216. By means of the electromagnetic coupling, power is transmitted from the primary side to the secondary. The secondary resonant circuit 216 is connected to a rectifier circuit 218 (comprising for instance a bridge rectifier) and a subsequent DC/DC converter 224 generating a regulated DC output power.
In addition to the power transmission, the contactless connector system 200 is further equipped with means for establishing a bi-directional data link for transmitting data through the connector system 200. A primary side data communication interface 222 communicates with a primary external component connected to the power transmitting connector 202. A primary side data transceiver 224 having one or more antennas 226 converts the data signals from the communication interface 222 into radio signals and accordingly converts received radio signals into electrical data signals which are input into the communication interface 222.
The power receiving connector 204 is provided with a corresponding secondary data transceiver 228 having one or more antennae 230 which receive signals from the primary side and transmit signals from the secondary towards the primary side via a wireless near field radio link. A secondary data communication interface 232 is connected to the secondary data transceiver 228 for communicating with a second external component connected to the power receiving connector 204.
A primary control unit 234 controls the operation of the resonant circuit 210, the primary side data communication interface 222, and the primary side data transceiver 224.
Known contactless connector systems which transmit both power and data, however, can only be provided with updated firmware on the secondary power receiving side when there is sufficient power supply via the inductive transfer from the primary power transmitting side. Moreover, in known contactless connector systems, controlling a maximum output power requires a hardware modification.